Project Tanagra - Harvard Universityhea- · Project Tanagra Timing Analysis of Grating Data Vinay Kashyap (SAO) Jennifer Posson-Brown, Jeremy Drake, Kathy Reeves, Steve Saar (SAO),

Project TanagraTiming Analysis of Grating DataVinay Kashyap (SAO)Jennifer Posson-Brown, Jeremy Drake, Kathy Reeves, Steve Saar (SAO), Raymond Wong, Thomas Lee (UC Davis), Alanna Connors (Eureka), Jeff Scargle (NASA/Ames)

1Tuesday, December 13, 2011

Darmok


Darmok and Jalad at Tanagra


Lightcurves and spectra with Chandra

A different kind of datasetgrating observations made with Chandra X-ray Telescope

A bountiful spectro-temporal mine to dig


A different kind of dataset

peer-selected “interesting” bright X-ray sources

long-duration observations

photons with wavelength and arrival time attributes

excellent spectral and timing resolution


HETGS+ACIS-S Grating Spectra

180 Chapter 8. HETG: Chandra High Energy Transmission Grating

Raw Detector Image, ACIS Energy Color-coded

MEG Minus-First Order Spectral Images19 A 15 A

9.25 A 6.7 A

12.2 A

17 A

HEG

MEG

MEG-minus spectrum

S0 S1 S2 S3 S4 S5

Aspect corrected Sky Image, Zeroth and First Orders Selected

Figure 8.1: HETGS observation of Capella, Obsid 1318. The top panel shows an imageof detected events on the ACIS-S detector with the image color indicating the ACIS-determined X-ray energy. The bright zeroth-order image is visible on CCD S3 and includesa trailed image (the vertical frame-transfer streak). Diffracted photons are visible forminga shallow “X” pattern; the HEG and MEG spectra are indicated. The images are broaddue to dither of the spacecraft. The middle panel shows an image after the data have beenaspect corrected and selections applied to include only valid zeroth and first-order events;note that the Y axis has been flipped from the normal Sky view to match the detectorcoordinates view in the top panel. Finally, the lower panel shows an expanded view of theMEG minus-first-order spectrum with emission lines clearly visible.


HETGS+ACIS-S Grating Spectra


HETGS+ACIS-S lightcurves


HETGS+ACIS-S lightcurves


Sounds grand.Why hasn’t anyone looked at all this yet?

Barriers to entry

few to none general algorithms to deal with (t,λ)

no “statistically complete” samples

all the easy bits already done by PI

do you really have to sit and stare at each observation?

I am on the lookout for algorithms


My Motivation

solar and stellar flare energies are distributed as power-laws, dN/dE ~ E-α, with α<2 for Sun, and α>2 for low-mass stars.

probably due to self-organized criticality in magnetic field structures

Questions: is α a function of spectral type? is a single power-law a consistently good description? is there a dependence of α on luminosity or on plasma temperature? where is the lower cut-off to the distribution?



Your Motivation

A different kind of data mining

Digging deep into a single source


Illustrative example: AU Mic


Illustrative example: AU MicJeff Scargle’s adaptive histogram


Illustrative example: Procyon


Illustrative example: Procyon

α ! 1.7


Illustrative example: FK Com

line centroid shifts with time


Illustrative example: FK Com

line centroid shifts with time


Summary

coherently reduced datasets with extraordinarily detailed timing and spectral information

multiple, independent, simultaneous data streams

will be extended to other types of objects (e.g., AGNs), observed with other missions (e.g., XMM-Newton/RGS)

test bed for deep (as opposed to broad) analysis methods

e.g., not just detect a transient, but study its characteristics in spectral lines formed at different temperatures


Documents

Project Tanagra - Harvard Universityhea- · Project Tanagra Timing Analysis of Grating Data Vinay Kashyap (SAO) Jennifer Posson-Brown, Jeremy Drake, Kathy Reeves, Steve Saar (SAO),